Severe flexible flatfeet with triceps surae complex shortening are prognostically unfavorable in early childhood and may compromise normal foot development.
This retrospective, IRB-approved study ...included 20 children (38 feet) under 6 years with severe flexible flatfeet and triceps surae complex shortening. Treatment included minimally invasive percutaneous achilles tendon lengthening followed by a 4-week cast fixation and corrective orthotic therapy under talo-navicular reposition for at least 6-months. Preoperative weightbearing x-rays and at the last available follow-up included anteroposterior talus-first metatarsal angle and lateral talus pitch, Meary’s and talocalcaneal angle and were compared to reference values. ROM, surgeon-rated clinical outcomes and complications/re-interventions were evaluated.
Age at surgery was 3.7 years (1.3–5.9 y) and follow-up time was 4.3 years (1.1–8.9 y). No complications occurred. Clinical outcome was good (68 %) to very good (26 %). Ratio of normal angles increased significantly for three angles. Dorsiflexion ROM improved from −5.0 ± 6.8° at baseline to 15.7 ± 7.6°.
With significant improvements in clinical and radiographic outcomes, minimal-invasive percutaneous Achilles tendon lengthening followed by orthotic therapy seems to be a valuable treatment option for selected preschool-aged patients with severe, flexible flatfeet with significantly shortened triceps surae.
IV
Purpose:
The conditions leading to growth rebound after hemiepiphysiodesis are still poorly understood. This article analyzes the radiographical outcomes after guided growth with tension band ...plating, using plates in idiopathic genu valgum patients and attempts to generate a predictive model of growth rebound.
Methods:
Patients with idiopathic genu valgum deformity who received tension band plating were selected for evaluation. We only analyzed coronal plane deformities. Only patients with a long-standing X-ray before tension band plating surgery, a long-standing X-ray at tension band plating removal, and a long-standing X-ray at the latest follow-up after tension band plating removal were considered for this study. The change of mechanical axis deviation between the tension band plating removal and the last follow-up was evaluated for rebound, and ordinal logistic regression was performed to determine the relevant variables for predictive modeling rebound growth.
Results:
Overall, 100 patients (189 legs) were analyzed. The mean mechanical axis deviation at tension band plating removal was 8.4 mm in varus direction, and the mean mechanical axis deviation at the last follow-up was −3.4 mm (p ≤ 0.001). However, 111 legs (59%) showed rebound growth, 57 (30%) stayed stable, and 21 (11%) showed a continuous correction. Six significant factors significantly influencing rebound were isolated which are clinically relevant: sex, age, baseline mechanical axis deviation, mechanical lateral distal femoral angle, and mechanical medial proximal tibial angle, and mechanical axis deviation correction rate. Mechanical axis deviation correction rate had the highest odds ratios. The machine learning classification model for predicting rebound growth built from the study data showed a misclassification rate of 39%.
Conclusion:
There was a high rate of rebound growth in this cohort, especially for patients at a young age at implantation. The highest risk factors for rebound growth were male sex, and high correction rates, such as found during peak growth spurt. The proposed classification model needs more data to improve its predictive power before it can be used in clinics.
Level of evidence:
Level III.
Recovery from COVID-19 is associated with production of anti-SARS-CoV-2 antibodies, but it is uncertain whether these confer immunity. We describe viral RNA shedding duration in hospitalized patients ...and identify patients with recurrent shedding. We sequenced viruses from two distinct episodes of symptomatic COVID-19 separated by 144 days in a single patient, to conclusively describe reinfection with a different strain harboring the spike variant D614G. This case of reinfection was one of the first cases of reinfection reported in 2020. With antibody, B cell and T cell analytics, we show correlates of adaptive immunity at reinfection, including a differential response in neutralizing antibodies to a D614G pseudovirus. Finally, we discuss implications for vaccine programs and begin to define benchmarks for protection against reinfection from SARS-CoV-2.
The knee has various pathologic appearances in patients with congenital longitudinal deformities of the lower extremities. Radiographs from 39 patients with unilateral longitudinal congenital ...deficiencies of the lower extremities were analyzed to describe epiphyseal and metaphyseal configurations and position of the epiphyseal plate. We defined 22 radiographic parameters of the femur and tibia, calculated the mean values, and compared the parameters of the affected knee with the unaffected knee for patients in different age groups. In the femur, we observed hypoplasia of the lateral condyle in width and height. In the tibia, the lateral condylar hypoplasia was manifest primarily by lateral horizontal deficiency. Age group comparisons showed no horizontal epiphyseal deficiencies in the older patients, but there was persistence of vertical epiphyseal deficiencies. Bony deformities in congenital longitudinal deficiencies mainly were attributable to dysplasia of the lateral epiphysis in the distal femur and proximal tibia, whereas positions of the epiphyseal plate had varying physiologic values.
Diagnostic study, Level II. See the Guidelines for Authors for a complete description of levels of evidence.
Within 1 AU from Jupiter, the dust detector aboard the Ulysses spacecraft during the flyby on February 8, 1992 recorded periodic bursts of submicron dust particles with durations ranging from several ...hours to two days and occurring at about monthly intervals. These particles arrived at Ulysses in collimate streams radiating from close to the line-of-sight direction to Jupiter, suggesting a Jovian origin for the periodic bursts. Ulysses also detected a flux of micron-sized dust particles moving in high-velocity retrograde orbits. These grains are identified here as being of interstellar origin.
New pathophysiological insights
Based on improved knowledge of the vascular supply of the proximal femur, a safe surgical dislocation of the hip joint was established allowing direct insights to the ...pathomorphological malfunctioning of the joint. One insight was that slipped capital femoral epiphysis (SCFE) impingement leads to substantial damage of the chondrolabral rim area, even in the presence of minor slips. A further surgical development was the extended retinacular flap allowing for correction of the deformity with calculable risk for iatrogenic necrosis.
Consecutive surgical concept
In 20 years of experience, a treatment concept for SCFE could be established which replaces classic pinning in situ and indirect correction of the deformity with subcapital re-alignment when the physis is still open, with true femoral neck osteotomy for hips with closed physis. Pinning in situ still has a place in minor slips but should be combined with open or arthroscopic recreation of an anterior metaphyseal waisting.
Unexpected complication
Loss of joint stability is a rare complication of anatomic re-alignment. It can be disease-related when the impingement has induced severe destruction of acetabular cartilage. It can be related to the surgical procedure, especially when the neck was excessively shortened and refixation of the trochanter was not advanced. Finally, in cases with severe and long-lasting deformity, the acetabulum may undergo adaptive flattening, being the cause of joint destabilisation with the correction of the deformity. Advancement of the greater trochanter and/or peri-acetabular osteotomy may be discussed to restabilise the joint.
A 16-year-old boy sustained a traumatic posterior dislocation of the right hip. After initial closed reduction, the hip spontaneously redislocated within 2 days. Four days after the initial ...dislocation, the patient was transferred to the authors’ institution, where a radiographic workup showed a severe capsular and labral disruption from the posterior aspect of the acetabulum. Subsequently, the patient underwent operative treatment using the technique of surgical hip dislocation through a digastric osteotomy as described by Ganz. Using this approach, the avulsed capsulolabral complex as well as the pathological head–neck junction, which is suspected to be a lever for the femoral head, could be fully addressed. The authors recommend further radiographic studies to evaluate the underlying pathology in traumatic dislocation of the hip as well as the described surgical approach, which leads to successful treatment of the entire pathology.
Cases of developmental dislocation of the hip occur after walking age because of late or missed diagnosis and failed conservative or operative treatment. Although a general consensus exists for the ...treatment in infants up to the age of 18 months, the recommendations for the treatment of developmental dislocation of the hip in older children range from conservative treatment up to 3 years of age to primary surgical procedures from the age of 18 months. A review of the pertinent literature and of the different treatment options was performed and the authorsʼ preferred treatment regime and techniques for the operative treatment of developmental dislocation of the hip after walking age are reported.
THE MINIATURISATION OF THE 4-POINT-BEND TEST Lube, T.; Manner, M.; Danzer, R.
Fatigue & fracture of engineering materials & structures,
November 1997, Letnik:
20, Številka:
11
Journal Article
Recenzirano
Odprti dostop
— Strength measurements are becoming increasingly important for electroceramics. Bending of specimens small enough to be cut out of small electroceramic components may be one possibility. Therefore ...the miniaturisation of the 4‐point bend‐test for ceramic specimens is now being attempted. In this paper the errors in determining the flexural strength arising from the test principle itself, plus the geometry and measuring inaccuracies are calculated and expressed as a function of the outer span length. Contact pressure and a tolerable total measuring inaccuracy determines the dimensions of miniature specimens and fixtures. The possibilities of appropriate specimen preparation are also investigated.
Ceramic materials show a volume (i.e. a specimen size) dependence of strength which is described by Weibull's statistical theory. The applicability of the miniature bend‐fixtures is demonstrated by measuring this volume effect.
Background: A vegetarian diet is considered to promote health and longevity and reduce the risk of cardiovascular diseases and cancer. However, a vegetarian diet may be deficient in some nutrients. ...Exclusion of animal products in vegetarian diets may affect the status of certain B-vitamins, and further cause the rise of plasma homocysteine concentration. Objective: The nutritional status of various B-vitamins (B 1 , B 2 , B 6 , B 12 , folic acid) and the concentration of homocysteine in blood plasma of omnivores (n = 40), vegetarians (n = 36) and vegans (n = 42) in Austria was evaluated. Methods: The evaluation was done using the functional parameters erythrocyte transketolase (ETK), glutathione reductase (EGR) and glutamic oxaloacetic transaminase (EGOT) activation coefficients. Enzyme activity was measured photometrically. The quantity of vitamins B 1 , B 2 and B 6 in urine and the concentrations of vitamin B 6 and homocysteine in plasma were determined by HPLC methods with fluorescence detection. Plasma concentration of vitamin B 12 and folic acid were measured with radioimmunoassay. Results: Most of the subjects showed a satisfying vitamin B 1 status. Vegans presented a significantly lower mean plasma vitamin B 12 concentration than omnivores and vegetarians and deficiency in 2.4% of the volunteers but the highest mean value of plasma folate among the investigated groups. A deficient status of folate was found in 18% of omnivores and in approximately 10% of vegans and vegetarians. The status of riboflavin is considered to be deficient in about 10% of omnivores and vegetarians and in over 30% of vegans. According to the activation coefficient of GOT, approximately one third of all subjects showed vitamin B 6 deficiency. Elevated homocysteine concentration in plasma was observed in 66% of the vegans and about 45–50% of the omnivores and vegetarians. Vegan subjects had significantly higher mean plasma homocysteine levels than omnivores. Conclusion: Thiamin and folate need not be a problem in a well-planned vegan diet. Vitamins B 12 and B 2 may need attention in the strict vegan diet, especially regarding elevated homocysteine levels in plasma. Pyridoxine status appeared to be independent of the diet.
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